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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /third_party/rust/viaduct/src/backend | |
parent | Initial commit. (diff) | |
download | firefox-esr-upstream.tar.xz firefox-esr-upstream.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'third_party/rust/viaduct/src/backend')
-rw-r--r-- | third_party/rust/viaduct/src/backend/ffi.rs | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/third_party/rust/viaduct/src/backend/ffi.rs b/third_party/rust/viaduct/src/backend/ffi.rs new file mode 100644 index 0000000000..cca6bc68f2 --- /dev/null +++ b/third_party/rust/viaduct/src/backend/ffi.rs @@ -0,0 +1,209 @@ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +use crate::{backend::Backend, settings::GLOBAL_SETTINGS}; +use crate::{msg_types, Error}; +use ffi_support::{ByteBuffer, FfiStr}; + +ffi_support::implement_into_ffi_by_protobuf!(msg_types::Request); + +impl From<crate::Request> for msg_types::Request { + fn from(request: crate::Request) -> Self { + let settings = GLOBAL_SETTINGS.read(); + msg_types::Request { + url: request.url.to_string(), + body: request.body, + // Real weird that this needs to be specified as an i32, but + // it certainly makes it convenient for us... + method: request.method as i32, + headers: request.headers.into(), + follow_redirects: settings.follow_redirects, + use_caches: settings.use_caches, + connect_timeout_secs: settings.connect_timeout.map_or(0, |d| d.as_secs() as i32), + read_timeout_secs: settings.read_timeout.map_or(0, |d| d.as_secs() as i32), + } + } +} + +macro_rules! backend_error { + ($($args:tt)*) => {{ + let msg = format!($($args)*); + log::error!("{}", msg); + Error::BackendError(msg) + }}; +} + +pub struct FfiBackend; +impl Backend for FfiBackend { + fn send(&self, request: crate::Request) -> Result<crate::Response, Error> { + use ffi_support::IntoFfi; + use prost::Message; + super::note_backend("FFI (trusted)"); + + let method = request.method; + let fetch = callback_holder::get_callback().ok_or(Error::BackendNotInitialized)?; + let proto_req: msg_types::Request = request.into(); + let buf = proto_req.into_ffi_value(); + let response = unsafe { fetch(buf) }; + // This way we'll Drop it if we panic, unlike if we just got a slice into + // it. Besides, we already own it. + let response_bytes = response.destroy_into_vec(); + + let response: msg_types::Response = match Message::decode(response_bytes.as_slice()) { + Ok(v) => v, + Err(e) => { + panic!( + "Failed to parse protobuf returned from fetch callback! {}", + e + ); + } + }; + + if let Some(exn) = response.exception_message { + return Err(Error::NetworkError(format!("Java error: {:?}", exn))); + } + let status = response + .status + .ok_or_else(|| backend_error!("Missing HTTP status"))?; + + if status < 0 || status > i32::from(u16::max_value()) { + return Err(backend_error!("Illegal HTTP status: {}", status)); + } + + let mut headers = crate::Headers::with_capacity(response.headers.len()); + for (name, val) in response.headers { + let hname = match crate::HeaderName::new(name) { + Ok(name) => name, + Err(e) => { + // Ignore headers with invalid names, since nobody can look for them anyway. + log::warn!("Server sent back invalid header name: '{}'", e); + continue; + } + }; + // Not using Header::new since the error it returns is for request headers. + headers.insert_header(crate::Header::new_unchecked(hname, val)); + } + + let url = url::Url::parse( + &response + .url + .ok_or_else(|| backend_error!("Response has no URL"))?, + ) + .map_err(|e| backend_error!("Response has illegal URL: {}", e))?; + + Ok(crate::Response { + url, + request_method: method, + body: response.body.unwrap_or_default(), + status: status as u16, + headers, + }) + } +} + +/// Type of the callback we need callers on the other side of the FFI to +/// provide. +/// +/// Takes and returns a ffi_support::ByteBuffer. (TODO: it would be nice if we could +/// make this take/return pointers, so that we could use JNA direct mapping. Maybe +/// we need some kind of ThinBuffer?) +/// +/// This is a bit weird, since it requires us to allow code on the other side of +/// the FFI to allocate a ByteBuffer from us, but it works. +/// +/// The code on the other side of the FFI is responsible for freeing the ByteBuffer +/// it's passed using `viaduct_destroy_bytebuffer`. +type FetchCallback = unsafe extern "C" fn(ByteBuffer) -> ByteBuffer; + +/// Module that manages get/set of the global fetch callback pointer. +mod callback_holder { + use super::FetchCallback; + use std::sync::atomic::{AtomicUsize, Ordering}; + + /// Note: We only assign to this once. + static CALLBACK_PTR: AtomicUsize = AtomicUsize::new(0); + + // Overly-paranoid sanity checking to ensure that these types are + // convertible between each-other. `transmute` actually should check this for + // us too, but this helps document the invariants we rely on in this code. + // + // Note that these are guaranteed by + // https://rust-lang.github.io/unsafe-code-guidelines/layout/function-pointers.html + // and thus this is a little paranoid. + ffi_support::static_assert!( + STATIC_ASSERT_USIZE_EQ_FUNC_SIZE, + std::mem::size_of::<usize>() == std::mem::size_of::<FetchCallback>() + ); + + ffi_support::static_assert!( + STATIC_ASSERT_USIZE_EQ_OPT_FUNC_SIZE, + std::mem::size_of::<usize>() == std::mem::size_of::<Option<FetchCallback>>() + ); + + /// Get the function pointer to the FetchCallback. Panics if the callback + /// has not yet been initialized. + pub(super) fn get_callback() -> Option<FetchCallback> { + let ptr_value = CALLBACK_PTR.load(Ordering::SeqCst); + unsafe { std::mem::transmute::<usize, Option<FetchCallback>>(ptr_value) } + } + + /// Set the function pointer to the FetchCallback. Returns false if we did nothing because the callback had already been initialized + pub(super) fn set_callback(h: FetchCallback) -> bool { + let as_usize = h as usize; + match CALLBACK_PTR.compare_exchange(0, as_usize, Ordering::SeqCst, Ordering::SeqCst) { + Ok(_) => true, + Err(_) => { + // This is an internal bug, the other side of the FFI should ensure + // it sets this only once. Note that this is actually going to be + // before logging is initialized in practice, so there's not a lot + // we can actually do here. + log::error!("Bug: Initialized CALLBACK_PTR multiple times"); + false + } + } + } +} + +/// Return a ByteBuffer of the requested size. This is used to store the +/// response from the callback. +#[no_mangle] +pub extern "C" fn viaduct_alloc_bytebuffer(sz: i32) -> ByteBuffer { + let mut error = ffi_support::ExternError::default(); + let buffer = + ffi_support::call_with_output(&mut error, || ByteBuffer::new_with_size(sz.max(0) as usize)); + error.consume_and_log_if_error(); + buffer +} + +#[no_mangle] +pub extern "C" fn viaduct_log_error(s: FfiStr<'_>) { + let mut error = ffi_support::ExternError::default(); + ffi_support::call_with_output(&mut error, || { + log::error!("Viaduct Ffi Error: {}", s.as_str()) + }); + error.consume_and_log_if_error(); +} + +#[no_mangle] +pub extern "C" fn viaduct_initialize(callback: FetchCallback) -> u8 { + ffi_support::abort_on_panic::call_with_output(|| callback_holder::set_callback(callback)) +} + +/// Allows connections to the hard-coded address the Android Emulator uses for +/// localhost. It would be easy to support allowing the address to be passed in, +/// but we've made a decision to avoid that possible footgun. The expectation is +/// that this will only be called in debug builds or if the app can determine it +/// is in the emulator, but the Rust code doesn't know that, so we can't check. +#[no_mangle] +pub extern "C" fn viaduct_allow_android_emulator_loopback() { + let mut error = ffi_support::ExternError::default(); + ffi_support::call_with_output(&mut error, || { + let url = url::Url::parse("http://10.0.2.2").unwrap(); + let mut settings = GLOBAL_SETTINGS.write(); + settings.addn_allowed_insecure_url = Some(url); + }); + error.consume_and_log_if_error(); +} + +ffi_support::define_bytebuffer_destructor!(viaduct_destroy_bytebuffer); |